At present, a fuel cell system including a fuel cell which receives supply of a reactive gas (a fuel gas and an oxidizing gas) to generate a power has been suggested and put to practical use. Such a fuel cell system is provided with a fuel supply channel for supplying, to the fuel cell, the fuel gas supplied from a fuel supply source such as a hydrogen tank.
Moreover, in general, the fuel supply channel is provided with a pressure adjustment valve (a regulator) which reduces, to a constant value, a supply pressure of the fuel gas from the fuel supply source, in a case where the supply pressure is remarkably high (e.g., see Japanese Patent Application Laid-Open No. 2004-342386).